The present invention relates generally to springs, such as leaf springs or the like, that have a gap, such as a scarf gap or the like, resulting from their manufacture and associated bushings or the like. More specifically, the present invention relates to a spring eye scarf gap protector device, an associated elastomeric bushing assembly, and associated methods.
Springs, such as leaf springs or the like, typically have a gap, such as a scarf gap or the like, resulting from their manufacture. This gap is formed when the metal or other material of the spring is bent, shaped, or otherwise formed and the ends and/or surfaces of the spring come into contact with one another, such as when a spring eye is formed. This gap becomes problematic when a bushing or the like is disposed within the spring eye. Such bushings are typically made of an elastomeric material and, when disposed within the spring eye, the sharp, irregular edges of the gap may abrade or otherwise damage the bushing, detrimentally affecting its elastomeric and/or fatigue properties.
One possible solution to this problem is to dispose the bushing within a rigid sleeve or the like. This rigid sleeve may be made of a metal, such as steel, a plastic, a composite material, or the like. Both the bushing and the rigid sleeve are then disposed within the spring eye, the rigid sleeve protecting the bushing from the sharp, irregular edges of the gap. This solution, however, is itself problematic as it may make installation of the bushing in the spring eye more difficult, the bushing may be inadequately retained in the spring eye, the bushing may be allowed to rotate within the spring eye, or metal-to-metal contact, for example, may be otherwise undesirable.
Thus, what is needed is a device that protects the elastomeric bushing from the sharp, irregular edges of the gap in the spring eye, without the use of a rigid sleeve or the like. What is also needed is a device that is relatively simple and cost-effective to manufacture, install, and ship, alone or in combination with the bushing as part of an elastomeric bushing assembly.
The spring eye scarf gap protector device of the present invention incorporates a rigid member into the elastomeric bushing described above. This rigid member, which may be made of a metal, such as steel, a plastic, a composite material, or the like, securely engages one or more recesses manufactured into the bushing. For example, the rigid member may be xe2x80x9csnappedxe2x80x9d or press-fit into and/or bonded with the one or more recesses. The resulting elastomeric bushing assembly may then be shipped to a customer or the like with the rigid member in place and installed into the spring eye of a leaf spring or the like. Upon installation, the elastomeric bushing bulges, accommodating the volume or space between an inner member or structure and the inner diameter of the spring eye. Advantageously, the elastomeric material adjacent to the rigid member applies compressive force to the rigid member, pushing it against the scarf gap of the spring eye. Thus, there is no elastomeric material in contact with the sharp, irregular edges of the scarf gap, preventing abrading or damage to the elastomeric bushing assembly.
In one embodiment of the present invention, an elastomeric bushing assembly includes a substantially cylindrical elastomeric bushing segment having a recessed channel manufactured into a portion of an outer surface thereof and a rigid member disposed within the recessed channel manufactured into the portion of the outer surface of the substantially cylindrical elastomeric bushing segment. The substantially cylindrical elastomeric bushing segment is configured such that it may be disposed within a first structure comprising an inner surface having edges defining a gap and the substantially cylindrical elastomeric bushing segment is configured such that it may receive a second structure comprising an outer surface. The substantially cylindrical elastomeric bushing segment is configured such that it may be disposed within the first structure comprising the inner surface having edges defining the gap such that the rigid member is substantially aligned and in direct contact with the edges defining the gap. In an alternative embodiment of the present invention, the elastomeric bushing assembly includes a plurality of substantially cylindrical elastomeric bushing segments each having a recessed channel manufactured into a portion of an outer surface thereof, wherein the recessed channels manufactured into the portion of the outer surface of each of the plurality of substantially cylindrical elastomeric bushing segments are substantially aligned. The first structure may be, for example, a leaf spring comprising an inner surface having edges defining a scarf gap.
In another embodiment of the present invention, a spring assembly includes a first structure comprising an inner surface having edges defining a gap, a substantially cylindrical elastomeric bushing segment disposed within the inner surface of the first structure, the substantially cylindrical elastomeric bushing segment having a recessed channel manufactured into a portion of an outer surface thereof, and a rigid member disposed within the recessed channel manufactured into the portion of the outer surface of the substantially cylindrical elastomeric bushing segment, wherein the rigid member is substantially aligned and in direct contact with the edges of the inner surface of the first structure defining the gap. The substantially cylindrical elastomeric bushing segment is configured such that it may receive a second structure comprising an outer surface. In an alternative embodiment of the present invention, the spring assembly includes a plurality of substantially cylindrical elastomeric bushing segments disposed within the inner surface of the first structure, the plurality of substantially cylindrical elastomeric bushing segments each having a recessed channel manufactured into a portion of an outer surface thereof, wherein the recessed channels manufactured into the portion of the outer surface of each of the plurality of substantially cylindrical elastomeric bushing segments are substantially aligned. The first structure may be, for example, a leaf spring comprising an inner surface having edges defining a scarf gap.
In a further embodiment of the present invention, a method for providing an elastomeric bushing assembly includes the steps of providing a substantially cylindrical elastomeric bushing segment, manufacturing a recessed channel into a portion of an outer surface of the substantially cylindrical elastomeric bushing segment, and disposing a rigid member within the recessed channel manufactured into the portion of the outer surface of the substantially cylindrical elastomeric bushing segment. The method also includes the steps of configuring the substantially cylindrical elastomeric bushing segment such that it may be disposed within a first structure comprising an inner surface having edges defining a gap and configuring the substantially cylindrical elastomeric bushing segment such that it may receive a second structure comprising an outer surface. The method further includes disposing the substantially cylindrical elastomeric bushing segment within the first structure comprising the inner surface having edges defining the gap such that the rigid member is substantially aligned and in direct contact with the edges defining the gap. In an alternative embodiment of the present invention, the method includes the step of providing a plurality of substantially cylindrical elastomeric bushing segments each having a recessed channel manufactured into a portion of an outer surface thereof, wherein the recessed channels manufactured into the portion of the outer surface of each of the plurality of substantially cylindrical elastomeric bushing segments are substantially aligned. The first structure may be, for example, a leaf spring comprising an inner surface having edges defining a scarf gap.